Table 1.

Silicosis patient clinical characteristics

Patient	Age	First silica exposure year	Exposure duration (months)	FEV1 (% predicted)	FVC (% predicted)	FEV1/FVC ratio	Chest X-ray severity score	Chest X-ray large opacities	Smoking history (Pack years)
C1	38	NA							15
C2	43	NA							5
C3	29	NA							2
C4	27	NA							0
C5	29	NA							2
C6	40	NA							18
C7	38	NA							10
C8	40	NA							9
C9	42	NA							15
C10	28	NA							0
P1	29	2003	72	83	83	86	8	-	8
P2	36	1996	48	62	93	56	11	A	15
P3	35	2000	60	42	68	53	12	C	7
P4	28	2000	60	44	90	40	11	A	0
P5	34	2002	48	65	73	75	12	-	9
P6	31	2001	60	58	76	66	10	B	20
P7	38	1996	24	92	102	75	11	-	5
P8	34	1996	84	73	91	84	9	-	25
P9	37	2000	60	64	78	68	12	C	5
P10	36	2004	24	96	110	74	11	-	7
P11	36	2001	24	78	87	76	9	-	10
P12	34	1999	41				8	-	5
P13	38	2003	24	78	95	69	7	-	40
P14	49	2000	60	76	102	60	5	-	40
P15	33	2001	12	92	91	85	9	-	17
P16	36	1997	72	39	57	58	12	B	0
P17	30	2000	60	53	73	62	12	B	6
P18	29	2003	24	66	83	69	10	A	15
P19	33	2001	48	42	48	73	12	C	10
P20	35	2000	60	38	71	45	12	C	5
P21	34	2000	36	18	33	46	12	C	1

All 21 patients with silicosis (P1–P21) were males, as were the 10 healthy controls (C1–C10)

Radiological severity score according to International Labor Organization (ILO) small profusion subcategories (1–12, 12 represents the most extensive disease, which is 3/ + , highest profusion of small opacities subcategory). A large opacity is defined as an opacity having the longest dimension exceeding 10 mm. The size increases from A to C and reflects the severity of radiological involvement

FEV1, forced expiratory volume at 1.0 s; FEV1%, ratio of FEV1 to FVC, forced vital capacity; FEV1% predicted, FEV1% of the patient divided by the average FEV1% in the equivalent population; NA: not applicable in the healthy controls